I'hivnn^ania. 



Gymnosperms. 

 Cycadaceie. ConilVr; 



Moiiocntylt.Ml.uis. I I)i(ut\lpa..iiM. 



FIFTH ANNUAL RKPOIIT PI-. LVII 



All ¥i't;etati(ui. 



lM No. 2. 



IE PRINCIPAL TYPES OF VEGETATION IN GEOLOGIC TIME. 



